Apparatus for manufacturing mineral wool fibers and the like



Sept. 18, 1962 M. s. FIRNHABER 3,054,140

APPARATUS FOR MANUFACTURING MINERAL WOOL FIBERS AND THE LIKE Filed Feb.20, 1961 2 Sheets-Sheet 1 ATTORNEYS.

Sept. 18, 1962 M. s. FIRNHABER APPARATUS FOR MANUFACTURING MINERAL WOOLFIBERS AND THE LIKE Filed Feb. 20, 1961 2 Sheets-Sheet 2 m R mm MH Wm ma6 a w I m 4 a M M M W w IL H n 00\ M ll E U n q Ir] 3 a 2 /2 a3 (/U 2 Zzxxzzz ATTORNEYS.

United States Patent 3 054,140 APPTUS FOR MANUFACTURING MINERAL WOOLFIBERS AND 'll-E LIKE Miles 53. Firuhaher, Rte. 3, Pewauiree, Wis. FiledFeb. 20, 1961, Ser. No. 90,535 Claims. ((31. 18-26) This inventionrelates to an improved apparatus for manufacturing mineral wool fibersand the like, and more particularly to a fiberizing rotor especiallyadapted to produce thin, long, high-quality fibers.

The apparatus comprising the present invention is generally similar tothose disclosed in copending applications Serial No. 801,533, filed May24, 1959, and Serial No. 19,209, filed April 1, 1960, and the presentinvention is intended primarily as an improvement on said prior devices.

In the operation of a fiberizing apparatus of the general type hereinconcerned molten glass or similar thermoplastic material is thrown froma rapidly spinning rotor by centrifugal force, and as said materialleaves the rotor periphery it is acted upon by a high-velocity blast ofsteam or other fiberizing agent to produce the thin fibers used inmineral wool and similar products. With conventional fiberizing rotors,however, it has been found that a substantial number of incompletelyformed fibers, or so:- called slugs, are produced, which lessens thequality of the finished product, or the fibers are of a larger diameterthan is desired.

With the above in mind, the principal object of the present invention isto provide a novel fiberizing rotor assemblage wherein the moltenmaterial is passed through an annular, wire mesh screen as it leaves theperiphery of the rotor, in order to attenuate and reduce the diameter ofthe fibers, and to prevent any unforme'd globules or slugs from findingtheir way into the finished product.

A further object is to provide a rotor assemblage having novel means fordetachably securing said annular screen thereon, the detachable natureof said mounting permitting said screen to be quickly and easilyreplaced in the event it is damaged or worn.

A further object is to provide a rotor assemblage utilizing a fine meshscreen to promote the production of thin, perfectly-formed fibers, asdescribed, which assemblage includes means for continuously directingheat against said annular screen to prevent the molten material fromsolidifying thereon and clogging said screen.

A further object of the invention is to provide a fiberizing rotorassemblage having special material-retaining means thereon to preventthe molten material from escaping over the edge of the rotor rim withoutfirst being passed through the attenuating screen, and which novelretaining means also permit the present rotor to be mounted on ahorizontal axis, in contrast to the vertical axis which might otherwisebe necessary.

A further object is to provide a rotor assemblage constructed entirelyof metal, said rotor having special integral cooling means therein toprevent overheating and structural deterioration of the metal.

A further object of the invention is to provide an improved rotorassemblage wherein all of the major components can be separatelydetached and replaced in the event they become worn or broken, therebyeliminating the necessity of replacing the entire assemblage, as isrequired with conventional rotors.

A further object is to provide a fiberizing apparatus wherein thetemperature and viscosity of the molten material can be effectivelycontrolled during the fiberizing operation, thereby insuring that thefibers produced are of a consistently fine variety.

3,054,149 Patented Sept. 18, 1962 Still further objects of the presentinvention are to provide a fiberizing apparatus which is relativelysimple in design and construction, and which is reliable and efiicientin operation.

With the above and other objects in view, the invention consists of theimproved fiberizing apparatus for use in manufacturing mineral woolfibers and the like, and all of its parts and combinations, as set forthin the claims, and all equivalents thereof.

In the accompanying drawing, illustrating a complete embodiment of thepreferred form of the invention and twomodifications thereof, andwherein the same reference numerals designate the same parts in all ofthe views:

FIG. 1 is a view, principally in vertical section, of the fiberizingapparatus comprising the principal form of the invention;

FIG. 2 is an end view of the apparatus illustrated in FIG. 1;

FIG. 3 is a fragmentary vertical sectional view showing a modificationof the principal form of the invention; and

FIG. 4 is a vertical sectional view showing a modification wherein therotor is mounted on a vertical axis.

Referring now more particularly to FIG. 1 of the drawings, it will beseen that the apparatus comprising the present invention includesacup-shaped rotor head 11 having a material-receiving cavity 12 in itsforward face which is positioned to receive molten material from adelivery trough vl0. Said rotor head is mounted on a hollow,horizontally-disposed drive shaft 13 which is rotatably drivablyconnected to a motor or other prime mover (not shown), and which shaftis adapted to rotatably drive said rotor head at a high speed. Asillustrated, said drive shaft 13 projects into and completely throughthe rotor head and has a nut 15 threaded onto its outer end to removablyretain said rotor head thereon. That portion of the drive shaftextending through the rotor head is tapered slightly to provide a tight,wedge fit and to insure a positive driving engagement with the rotorhead. A smaller, concentric hollow tube 14 is carried within said driveshaft 13 and during the operation of the rotor, as will be hereinafterdescribed in greater detail, cold water is pumped through said smallertube and circulates between said tube and the surrounding shaft 13 asindicated by the arrows in FIG. 1. The result is a water jacket whichnot only maintains the drive shaft relatively cool, but which extendsinto and through the rotor head and also prevents the metal interior ofsaid rotor head from becoming overheated.

Like the rotor illustrated and described in the aforementioned copendingapplication Serial No. 19,209, the present assemblage is preferablyformed entirely of metal, rather than a combination of metal andrefractory materials as is used in conventional fiberizing rotors. Mostprior rotors have been constructed at least partially of ceramicmaterials. Ceramic materials, however, tend to dry out and crack in ashort time, necessitating their frequent replacement, and are veryunsatisfactory for this reason. With the present invention, however, dueto the novel integral cooling system hereinabove described, whichprevents the interior of the rotor from becoming overheated, the presentrotor can be constructed entirely of metal and there is no necessity foremploying inferior ceramic materials.

With reference again to FIG. 1, it will be seen that the forwardperiphery or rim of the cup-shaped rotor head 11 is provided with a pairof forwardly-projecting annular rim extensions 16 and 19. Said rimextensions are an important feature of the invention as they perform thedual function of providing mounting means for the novelfiber-attenuating screen hereinafter described, and in addition, theyprevent molten material from escaping prematurely from thevertically-disposed material-receiving cavity of the rotor head.

The inner rim extension 16 extends forwardly beyond the rotor rim ashort distance, and is provided with spaced slotted apertures 17 whichare obliquely angled outwardly in the direction of rotation tofacilitate the passage of the molten material therethrough, as will beseen. Formed on the forward edge of said rim extension is an inturnedannular lip or flange 18 which is designed to minimize the amount ofmolten material which escapes over the rim without passing through saidapertures 17. The outer annular rim extension 19 is concentric with andprojects forwardly beyond said inner rim extension, and is provided withan inner set of elongated apertures 20 similar to and in registrationwith the apertures 17 in said inner rim member. Said outer rim extensionalso has a second or outer set of apertures 20 forwardly of the inturnedlip 18 on said inner rim; and formed on the outer end of said member 19is a second annular inturned lip or flange 21 designed to further insureagainst loss of molten material. Said annular rim extensions 16 and 19are removably secured to the exterior of the rotor head by screws 23which can be quickly removed when it is desired to remove and replacesaid rim members.

Carried between the rim extensions 16 and 19, and held in clampingengagement thereby, is a fine wire mesh screen 22. Said screen ispreferably formed of a platinum-rhodium alloy, which is well adapted towithstand intense heat, and which preferably has a mesh of between .002and .035 inch, although the exact composition and specifications of saidscreening are not critical and may be varied to suit particularfiberizing requirements. A supplementary rim 24 (PEG. 1) is bolted orotherwise detachably secured to and within the outer rim extension 19 tohold the forward portion of the screen 22, said supplementary rim havingapertures 24- in registration with the apertures 20 in said outer rimextension.

As shown in FIGS. 1 and 2, the complete fiberizing apparatus alsoincludes a pair of concentric steam rings 25 and 26 which are mountedforwardly of and in surrounding relation to the periphery of the rotorhead 11. The smaller, inner ring 26 is provided with spaced apertures 27through which steam is emitted, and which apertures are positioned sothat the steam jets 28 (FIG. 1) will intercept the molten materialfilaments 32 just as the latter leave the periphery of the rotor. Theouter ring 25 functions as a distributor ring to ensure that the streamis distributed about the entire circumference of the inner ring 26 whichis in communication therewith.

To supplement and facilitate the fiberizing action of the steam ring 26,a plurality of burners 29 are also mounted in spaced relation about theperiphery of the rotor, said burners being designed to direct hot gasesor flames 30 against the molten filaments to maintain the same at theproper temperature and viscosity during the attenuating process. It isto be understood, of course, that while said ring 26 and burners 29 havebeen described as discharging steam, preheated air or any other suitablefiberizing agent may be employed as well, and the invention is not to belimited in this respect.

Mounted with ends adjacent the material-receiving cavity 12 of the rotorhead is another set of burners 31 which are positioned around the shaft13 to direct hot gas against the concave material-receiving surface ofthe rotor. Said burners not only direct heat against the molten materialin the rotor cavity, to maintain the same at a proper temperature and toprevent outside air from contacting and prematurely cooling the same,but due to the cup-like shape of said rotor cavity the hot gases emittedby said burners are deflected outwardly on the rotor rim and preventsaid molten material from solidifying on and clogging either the inneror outer portions of the wire screening 22 during the fiberizingoperation.

In the operation of the fiberizing apparatus, the molten materialdeposited in the material-receiving cavity 12 is flung radiallyoutwardly on the rotor head by centrifugal force, as described, and isdirected through the registering apertures in the rim extensions 16 and19, said apertures being angled outwardly in the direction of rotationto facilitate the passage of the molten material therethrough. As saidmaterial passes through said rim apertures it also passes through thewire mesh screen 22 carried between said rim extensions, and is formedthereby into relatively thin filaments. During the operation of therotor the inturned lip 18 on the inner rim extension 16 prevents most ofthe molten material from riding farther outwardly on the rotor rim andany molten material which should get past said first lip is caught bythe lip 21 on the outer rim extension, and is directed thereby throughthe apertures 20 which are kept heated and open by the discharge fromthe burners 31.

Immediately after said molten material filaments 32 (FIG. 1) passthrough said annular screen they are intercepted by the high-velocitysteam blast 28 emitted from the ring 26, which blast abruptly changesthe direction of said filaments and attenuates the same still more. Assaid fibers are being acted upon by said steam blast they are alsocontacted by the hot gases or flames 30 from the burners 29 whichprevent premature cooling and maintain said fibers at the propertemperature and viscosity during their attenuation. The result is thatthe fibers produced by the present invention are consistently fine,perfectly-formed fibers which are exceptionally well suited for use inproducts requiring a fine fiber.

As a result of said novel, coacting inturned lip members 18 and 21 onthe rotor rim, it has been found that the present rotor assemblage canbe mounted on a horizontal axis, as illustrated in FIG. 1, since themolten material is prevented by said lips from flowing out of theverticallydisposed material-receiving cavity 12 as described.

For some fiberizing operations the dual inturned lips 18 and 21 on therotor head of the principal form of the invention are not necessary andit is sutficient if a single inturned lip is employed. In suchinstances, as shown in FIG. 3, in which illustration the numeralsdesignating the structural members are the same as those in FIGS. 1 and2 preceded by the digit 1," the inner rim extension 116 is provided withan inturned lip 118 and the forward end of the outer rim extension 119terminates adjacent said lip. Thus the molten material is prevented fromescaping over the rotor rim solely by the lip 118, but the function andoperation of the apparatus is otherwise similar to that hereinabovedescribed, the molten material passing through the registering apertures117 and 120 in the rim extensions and through the screening 122 carriedtherebetween.

As illustrated in FIG. 4, it is also possible to advantageously employmany of the novel features characterizing the present invention in arotor mounted on a vertically-disposed drive shaft. Thevertically-mounted rotor shown in said FIG. 4 is generally similar tothat disclosed in the aforementioned copending application, Serial No.19,209, and the parts corresponding to those included in the principalform of the present invention (FIGS. 1 and 2) are preceded by the digit2.

Although the inturned lips 218 and 221 on the rim extensions illustratedin FIG. 4 are not as vital in a rotor which is mounted on a verticaldrive shaft, since there is less tendency for the material to escape thehorizontal material-receiving surface of the rotor, it still happenswith such rotors that a substantial number of unformed globules or slugsfind their way into the finished product. With the addition of theinturned lips 218 and 221, however, such occurrences are eliminated.Moreover, of course, the novel screen 222 ensures the production ofconsistently thin fibers, and is useful in either type of rotor. Theresult is that While the improved structure comprising the presentinvention is especially designed for use in a rotor assemblage mountedon a horizontal 5.) axis, the structure also has decided advantages in arotor mounted on a vertical axis.

From the foregoing detailed description it will be seen that the presentinvention provides an improved fiberizing apparatus which constitutes adefinite advancement in the art. Due to the use of an annular screen,the present rotor structure is not only designed to produce consistentlyfine, high-quality fibers of the type preferred in mineral wool andsimilar products, but there are no unformed fibers or slugs in thefinished product. In addition, due to the novel material-retaining lipsformed on the rotor head, the present structure can be mounted on ahorizontal drive shaft which is advantageous in certain situations.

Further advantages inherent in the present rotor assemblage are the factthat the entire structure can be easily and quickly disassembled and thevarious components individually replaced or repaired in the event ofdamage. This is not possible with most conventional fiberizing devices,and with the present rotor structure it is also possible to utilizemetal throughout, due to the novel cooling system employed therein, andit is unnecessary to use a combination of metal and ceramic materials,such as is used in conventional fiberizing devices.

It is to be understood, of course, that variations or modifications inthe construction of the apparatus hereinabove described will suggestthemselves to persons skilled in the art, and all of such variations ormodifica- .tions are contemplated as may come within the scope of thefollowing claims.

What I claim is:

1. In a fiberizing rotor having a rotatably mounted head with a concavematerial-receiving surface; an annular rim surrounding saidmaterial-receiving surface, said rim having apertures therethroughthrough which molten material flung centrifugally from said rotor headis intended to pass; an annular inturned lip on the outer edge of saidrim, and a second annular inwardly-projecting lip between said first lipand said material-receiving surface, there being apertures in the rimboth inwardly and outwardly of said second lip, said lips being adaptedto prevent molten material from escaping from said rotor head withoutpassing through said rim apertures.

2. A fiberizing rotor having a rotatably supported material-receivingmember with an outer material-receiving surface and having a periphery,an annular metal rim detachably secured around the periphery of saidmaterialreceiving member and having an annular portion projecting beyondsaid material-receiving surface and having an open outer end and havingan inturned annular lip, said projecting portion having relatively largeopenings therein, and a fine mesh screen of material which is more heatresistant than the material of the rim positioned against saidprojecting portion of the rim and covering said openings, the mesh ofsaid screen being of a size to attenuate molten material as the same isthrown centrifugally from the material-receiving surface and said meshproviding openings which are substantially smaller than the openings ofthe rim.

3. A fiberizing rotor having a rotatably supported material-receivingmember with an outer material-receiving surface and having a periphery,an annular metal rim detachably secured around the periphery of saidmaterialreceiving member and having an annular portion projecting beyondsaid material-receiving surface and having an open outer end, saidprojecting portion having relatively large openings therein, and a finemesh screen of material which is more heat resistant than the materialof the rim positioned against said projecting portion of the rim andcovering said openings, the mesh of said screen being of a size toattenuate molten material as the same is thrown centrifugally from thematerial-receiving surface and said mesh providing openings which aresubstantially smaller than the openings of the rim whereby there is amultiplicity of screen openings for each rim opening.

4. A fiberizing rotor having a rotatably supported material-receivingmember with an outer material-receiving surface and having a periphery,an annular metal rim secured around the periphery of saidmaterial-receiving member and having an annular portion projectingbeyond said material-receiving surface and having an open outer end,said projecting portion having relatively large openings therein, a finemesh screen of platinum rhodium alloy which is more heat resistant thanthe material of the rim positioned against said projecting portion ofthe rim and covering said openings, the mesh of said screen being of asize to attenuate molten material as the same is thrown centrifugallyfrom the material-receiving surface and said mesh providing openingswhich are substantially smaller than the openings of the 5. A fiberizingrotor having a rotatably supported material-receiving member with anouter material-receiving surface and having a periphery, an annularmetal rim secured around the periphery of said material-receiving memberand having an annular portion projecting beyond said material-receivingsurface and having an open outer end, said projecting portion havingrelatively large openings therein, a second annular metal rim securedaround the periphery of said material-receiving member and having anannular portion projecting beyond said materialreceiving surface andhaving openings in said projecting portion which are in registrationwith the openings of the first rim, and a fine mesh screen supportedbetween said two rim members whereby molten material throwncentrifugally through said registering openings of the rim members mustpass through the mesh of said screen.

6. A fiberizing rotor having a rotatably supported material-receivingmember with an outer material-receiving surface and having a periphery,an annular metal rim secured around the periphery of saidmaterial-receiving member and having an annular portion projectingbeyond said material-receiving surface and having an open outer end,said projecting portion having relatively large openings therein, asecond annular metal rim secured around the periphery of saidmaterial-receiving member and having an annular portion projectingbeyond said materialreceiving surface and having openings in saidprojecting portion which are in registration with the openings of thefirst rim, and a fine mesh screen of platinum-rhodium alloy supportedbetween said two rim members whereby molten material throwncen-trifugally through said registering openings of the rim members mustpass through the mesh of said screen.

7. A fiberizing rotor having a rotatably supported material-receivingmember with an outer material-receiving surface and having a periphery,an annular metal rim secured around the periphery of saidmaterial-receiving member and having an annular portion projectingbeyond said material-receiving surface and having an open outer end,said projecting portion having relatively large openings therein, asecond annular metal rim secured around the periphery of saidmaterial-receiving member and having an annular portion projectingbeyond said materialreceiving surface and having openings in saidprojecting portion which are in registration with the openings of thefirst rim, a fine mesh screen supported between said two rim memberswhereby molten material thrown centrifugally through said registeringopenings of the rim members must pass through the mesh of said screen,and means for directing heat against said screen to prevent moltenmaterial from solidifying thereon.

8. A fib-erizing rotor having a rotatably supported material-receivingmember with an outer material-receiving surface and having a periphery,an annular metal rim secured around the periphery of saidmaterial-receiving member and having an annular portion projectingbeyond said material-receiving surface and having an open outer end,said projecting portion having inner and outer sets of relatively largeopenings therein and having an inturned outer edge lip, a second annularmetal rim member detachably secured around the periphery of saidmaterialreceiving member within said first rim and having a portionwhich projects outwardly beyond the material-receiving surface a lesserdistance than the projecting portion of the first rim and having anannular inturned lip which is positioned between the lip of the firstrim and said material-receiving surface, said second rim havingopenings, in registration with the first set of openings of the firstrim, fine mesh screening positioned between said two rim members so thatmolten material passing through the first set of openings must passthrough the mesh of said screening, and fine mesh screening supportedover the second set of openings of said first rim member.

9. A fiberizing rotor having a rotatably supported material-receivingmember with an outer material-receiving surface and having a periphery,an annular metal rim detachably secured around the periphery of saidmaterialreceiving member and having an annular portion projecting beyondsaid material-receiving surface and having an open outer end, saidprojecting portion having inner and outer sets of relatively largeopenings therein and having an inturned outer edge lip, a second annularmetal rim member detachably secured around the periphery of saidmaterial-receiving member within said first rim and having a portionwhich projects outwardly beyond the material-receiving surface a lesserdistance than the projecting portion of the first rim and having anannular inturned lip which is positioned between the lip of the firstrim and said materialn'eceiving surface and between the first and secondsets of openings of said first rim, said second rim having openings inregistration with the first set of openings of the first rim, fine meshscreening positioned between said two rim members so that moltenmaterial passing through the first set of openings must pass through themesh of said screening, and fine mesh screening supported over thesecond set of openings of said rfirst rim member.

10. A fi berizing rotor having a rotatably supported material-receivingmember with an outer material-receiving surface and having a periphery,an annular metal rim detachably supported around the periphery of saidmaterialreceiving member for removal by movement axially of the rotorand having an annular portion projecting beyond said material-receivingsurface and having an open outer end and having an inturned annular lip,said projecting portion having relatively large openings therein, a finemesh screen of material which is more heat resist-ant than the materialof the rim positioned against said rim member whereby molten materialthrown centrifugally through said openings of the rim member must passthrough the mesh of said screen, said mesh providing openings which aresubstantially smaller than the openings of the rim whereby there is amultiplicity of screen openings for each rim opening, means fordetachably clamping the rim and screen in position around said rotorperiphery whereby the screen is supported against displacement by therim and whereby either the rim or screen may be readily replaced, andmeans for directing'heat against said screen to prevent molten materialfrom soliditying thereon.

References Cited in the file of this patent UNITED STATES PATENTS773,614 Westaway Nov. 1, 1904 2,192,944 Thomas Mar. 12, 1940 2,431,205Slayter Nov. 18, 1947 2,980,952 Stalego Apr. 25, 1961 2,980,954 Levecqueet a1, Apr. 25, 1961

